Regression coefficients (95% CIs) for cognitive test scores by bedtimes at age 7, cross-sectional analysis
| Bedtime | n | Mean | Model A | Model B | Model C | |||
|---|---|---|---|---|---|---|---|---|
| Girls | ||||||||
| Reading | ||||||||
| Before 19:30 | 488 | 112.4 | −0.17 | (−0.27 to −0.07) | −0.09 | (−0.18 to 0.00) | −0.09 | (−0.18 to 0.00) |
| 19:30–19:59 | 1083 | 116.0 | 0.03 | (−0.05 to 0.11) | 0.01 | (−0.06 to 0.08) | 0.00 | (−0.07 to 0.07) |
| 20:00–20:29 (ref) | 1713 | 115.3 | – | – | – | |||
| 20:30–20:59 | 814 | 113.1 | −0.12 | (−0.21 to −0.03) | −0.07 | (−0.15 to 0.01) | −0.06 | (−0.14 to 0.02) |
| 21:00–21:29 | 466 | 110.8 | −0.25 | (−0.34 to −0.15) | −0.13 | (−0.23 to −0.04) | −0.11 | (−0.20 to −0.01) |
| 21:30 or later | 85 | 107.6 | −0.42 | (−0.68 to −0.16) | −0.34 | (−0.63 to −0.06) | −0.33 | (−0.62 to −0.05) |
| Not regular | 434 | 108.6 | −0.38 | (−0.49 to −0.26) | −0.24 | (−0.34 to −0.14) | −0.22 | (−0.32 to −0.12) |
| Maths | ||||||||
| Before 19:30 | 495 | 9.4 | −0.18 | (−0.29 to −0.08) | −0.14 | (−0.23 to −0.04) | −0.14 | (−0.23 to −0.05) |
| 19:30–19:59 | 1105 | 9.8 | −0.03 | (−0.11 to 0.05) | −0.05 | (−0.12 to 0.02) | −0.06 | (−0.13 to 0.01) |
| 20:00–20:29 (ref) | 1738 | 9.9 | – | – | – | |||
| 20:30–20:59 | 819 | 9.6 | −0.12 | (−0.21 to −0.04) | −0.08 | (−0.15 to 0.00) | −0.07 | (−0.14 to 0.01) |
| 21:00–21:29 | 475 | 9.5 | −0.16 | (−0.27 to −0.04) | 0.00 | (−0.11 to 0.11) | 0.01 | (−0.10 to 0.11) |
| 21:30 or later | 85 | 9.6 | −0.12 | (−0.33 to 0.09) | 0.04 | (−0.19 to 0.27) | 0.05 | (−0.17 to 0.28) |
| Not regular | 440 | 8.8 | −0.39 | (−0.53 to −0.26) | −0.26 | (−0.39 to −0.14) | −0.26 | (−0.38 to −0.14) |
| Spatial | ||||||||
| Before 19:30 | 491 | 52.9 | −0.14 | (−0.24 to −0.04) | −0.08 | (−0.18 to 0.02) | −0.08 | (−0.17 to 0.02) |
| 19:30–19:59 | 1,106 | 54.0 | −0.04 | (−0.12 to 0.05) | −0.05 | (−0.12 to 0.03) | −0.05 | (−0.13 to 0.03) |
| 20:00–20:29 (ref) | 1,734 | 54.4 | – | – | – | |||
| 20:30–20:59 | 814 | 54.1 | −0.03 | (−0.12 to 0.06) | 0.01 | (−0.09 to 0.08) | 0.00 | (−0.09 to 0.08) |
| 21:00–21:29 | 474 | 53.1 | −0.12 | (−0.23 to −0.01) | 0.01 | (−0.10 to 0.12) | 0.01 | (−0.09 to 0.12) |
| 21:30 or later | 85 | 52.2 | −0.20 | (−0.42 to 0.01) | −0.10 | (−0.33 to 0.14) | −0.07 | (−0.31 to 0.17) |
| Not regular | 440 | 51.3 | −0.28 | (−0.42 to −0.14) | −0.15 | (−0.28 to −0.02) | −0.15 | (−0.28 to −0.03) |
| Boys | ||||||||
| Reading | ||||||||
| Before 19:30 | 411 | 110.1 | −0.09 | (−0.22 to 0.03) | 0.00 | (−0.12 to 0.11) | 0.01 | (−0.10 to 0.12) |
| 19:30–19:59 | 1,079 | 112.2 | 0.02 | (−0.06 to 0.11) | 0.01 | (−0.07 to 0.09) | 0.00 | (−0.07 to 0.08) |
| 20:00–20;29 (ref) | 1,791 | 111.7 | – | – | – | |||
| 20:30–20:59 | 840 | 111.9 | 0.02 | (−0.09 to 0.13) | 0.03 | (−0.08 to 0.13) | 0.03 | (−0.07 to 0.14) |
| 21:00–21:29 | 514 | 109.3 | −0.13 | (−0.25 to −0.02) | 0.00 | (−0.12 to 0.11) | 0.02 | (−0.10 to 0.13) |
| 21:30 or later | 76 | 111.1 | −0.03 | (−0.29 to 0.22) | 0.08 | (−0.14 to 0.31) | 0.14 | (−0.09 to 0.37) |
| Not regular | 448 | 107.8 | −0.21 | (−0.35 to −0.07) | −0.09 | (−0.23 to 0.05) | −0.05 | (−0.19 to 0.09) |
| Maths | ||||||||
| Before 19:30 | 418 | 9.6 | −0.10 | (−0.21 to 0.01) | −0.03 | (−0.14 to 0.09) | −0.01 | (−0.12 to 0.10) |
| 19:30–19:59 | 1,097 | 9.8 | −0.01 | (−0.09 to 0.07) | −0.03 | (−0.10 to 0.05) | −0.03 | (−0.11 to 0.05) |
| 20:00–20:29 (ref) | 1,808 | 9.9 | – | – | – | |||
| 20:30–20:59 | 853 | 10.0 | 0.03 | (−0.06 to 0.13) | 0.05 | (−0.05 to 0.14) | 0.05 | (−0.04 to 0.14) |
| 21:00–21:29 | 518 | 9.5 | −0.15 | (−0.27 to −0.03) | −0.02 | (−0.13 to 0.10) | 0.00 | (−0.12 to 0.12) |
| 21:30 or later | 77 | 9.2 | −0.25 | (−0.57 to 0.08) | −0.10 | (−0.43 to 0.24) | −0.07 | (−0.41 to 0.27) |
| Not regular | 456 | 9.6 | −0.12 | (−0.27 to 0.02) | 0.01 | (−0.13 to 0.16) | 0.04 | (−0.11 to 0.18) |
| Spatial | ||||||||
| Before 19:30 | 418 | 52.5 | −0.12 | (−0.24 to −0.01) | −0.06 | (−0.17 to 0.06) | −0.04 | (−0.15 to 0.07) |
| 19:30–19:59 | 1,098 | 54.2 | 0.03 | (−0.05 to 0.12) | 0.02 | (−0.06 to 0.10) | 0.01 | (−0.07 to 0.09) |
| 20:00–20:29 (ref) | 1,801 | 53.9 | – | – | – | |||
| 20:30–20:59 | 850 | 53.5 | −0.03 | (−0.13 to 0.06) | −0.01 | (−0.11 to 0.08) | −0.01 | (−0.10 to 0.09) |
| 21:00–21:29 | 519 | 50.7 | −0.29 | (−0.40 to −0.17) | −0.16 | (−0.27 to −0.06) | −0.14 | (−0.25 to −0.04) |
| 21:30 or later | 75 | 52.8 | −0.10 | (−0.34 to 0.14) | 0.07 | (−0.17 to 0.31) | 0.09 | (−0.15 to 0.32) |
| Not regular | 452 | 51.6 | −0.20 | (−0.33 to −0.07) | −0.07 | (−0.19 to 0.06) | −0.04 | (−0.17 to 0.09) |
Model A adjusts for child's age.
Model B additionally adjusts for interview season, school year, mother's age in years, birth order, languages spoken in the home, family income, highest parental qualification, mother's psychological distress, discipline strategies, mother often irritated with child, mother's parenting competence, breastfed, skips breakfast, musical activities at home, drawing/painting activities at home, helped with reading, TV hours per weekday, computer hours per weekday.
Model C additionally adjusts for parental employment, mother's view of amount of time with child, father's view of amount of time with child, child attends breakfast club, child attends after school club, any other childcare, child read to, child told stories, TV time rules, overcrowding, child wets bed, TV in bedroom.